SAN FRANCISCO – A plan by technology developer Mitchell Kapor to build a 6,478-square-foot house with a 10-car garage on a Berkeley hillside has moved a step closer to fruition as a result of a favorable state appeals court ruling.

A three-judge panel of the California Court of Appeal ruled in San Francisco on Wednesday that the plan by Kapor, the founder of Lotus Development Corp., and his wife, Freada Kapor Klein, did not need an environmental study under state law.

The couple’s proposal for the house and garage on a Rose Street lot with a 50 percent slope was approved by the Berkeley City Council in 2010.

A citizens’ group, Berkeley Hillside Preservation, and city resident Susan Nunes Fadley argued in an Alameda Superior Court lawsuit that the project required environmental study because of its size, scale and potential earthquake hazards.

A trial judge rejected the lawsuit, but in 2012 the Court of Appeal said the project presented unusual circumstances requiring study under the California Environmental Quality Act.

In March of this year, however, the California Supreme Court set aside that decision and sent the case back to the appeals court for further consideration. It said the intermediate court should have used a more stringent standard with more deference to the City Council when evaluating whether unusual circumstances existed.

In Wednesday’s decision, the appeals court said that under the guidance provided by the state high court, no environmental review was required.

The decision could be appealed to the state Supreme Court. Susan Brandt-Hawley, a lawyer for Berkeley Hillside Preservation, said, “We’re evaluating that,” and declined to comment further.

Palo Alto City Manager James Keene said one possibility involves the church applying for a conditional use permit to operate as a community center, which would legalize community service uses at the site so First Baptist Church could continue to have tenants such as girls choir groups and teen therapists.

The County of Santa Clara Housing Authority will buy and preserve the Buena Vista Mobile Home Park as affordable housing and the Jisser family will continue to own the commercial parts of the 6.19-acre site.